I really enjoy the way this is put together. I have written a number of javascript game engines, to play with over the years, and this hit a really nice spot between, I need to throw this whole thing to gether in the next 2 hours to entertain the kids, and the subsequent I really want to do a deep dive into the nitty gritty of this thing.
Looking forward to slapping a few quick games into this and distract the kids in a low bandwidth type style.
Adjacent points: I also think that selecting mature projects for your dependencies matters significantly. My old couchdb or early node work is generally defunct. On the other hand, I have some dotnet projects that are still functional with zero updates from a decade or more ago.
Additionally, it's reasonable to keep a copy of your dependencies somewhere in case the vendor dies, the licensing changes, or something else catastrophic happens. Even if you just image dev's machines when they offboard. There have been a few times this has prevented permanent project death or rewrite emergencies for me.
You're spending $16B to create $1T of real estate value.
That would pay for itself in two years at 1% R/E tax and <10% interest.
I didn't read the entire article, but the reason it won't happen at this scale is because you could never acquire the property rights to be able to do it, not because it's a bad investment.
I just wish the 4 billion we subsidize EVs with every year here in Norway were put to other use instead. Could habe built a new metro line every year for that amount of money. Which would have had a much larger long term effect.
That's the dream here in the states too. Our issue is that we have built our cities as enormous suburbs with such a low density that rail/transit isn't viable from a cost/person perspective. We tend to think of public transit a a business rather than as a service and our tax payers don't want to spend billions on not driving especially as our cost per mile is insane[0]. So, for the states EVs are basically the only way for us to ease out of 4000+sqft home on 4 acres and a 40 mile car commute and back into an built environment that does not require a car for all trips
They should be buying EVs for those who needs them such as rural area. For the rest of us, our quality of life would improve if we get rid of cars and densify areas.
At cold temps you lose range a few different ways:
First heat in an EV isn't free, this is usually where it gets you. People get in go "oh man its cold" and crank up the heat and there goes range. When you see one of the "this person ran out of power waiting in line at the Tesla charger in winter time" pictures this is how they did it.
Second battery efficiency goes down.
Finally, the battery usually is constantly doing the regen breaking thing but in cold weather it doesn't to save pack wear until you get the pack warm again
At least last time I checked, Teslas had rather anemic battery heaters. IIRC they’re around 6kW.
6kW is not enough to make a big dent in required mechanical braking, and it’s also not enough to quickly heat the battery pack, especially when operated intermittently.
I thought GP was referring to generating heat for HVAC, which is an interesting idea. I assume one challenge would be getting the warmth from the brakes to the cabin.
The problem is that cold batteries can't charge or discharge quickly. From the battery's point of view, regenerative braking is the same as fast charging (just for a very short period of time). When the battery is very cold (or almost full), Teslas regen as much as they can, then use the friction brakes to keep a consistent feel for one pedal driving. The battery does have fluid pumped through it for heating/cooling, but it can take some time before the pack is warm enough to charge/discharge at its rated capacity. The longest I've had a cold battery notice is 20 minutes, and that was after my car sat at 0ºF overnight.
My thought was to use the regen braking electricity for (more) resistive heating when it has nowhere else to go. It's an extra thing that only gets some use (depending on climate), but not a very expensive extra thing and takes some load off your pad/rotor brakes.
The battery is warmed by the heat pump (or if you have an older model, the resistive heating coils). That component can only take so much power. A more powerful heat pump would cost more, take up more space, and weigh more. My guess is that Tesla designed their heat pump based on these tradeoffs.
The density of air at 20ºC (293ºK) is 1.204kg/m^3. At -10ºC (263ºK) its density is 1.341kg/m^3, or 11% denser. For a Model 3 moving at 100kph, about half of its power is used to overcome air drag and half is used to overcome rolling resistance. Air drag is 1/2 * density * velocity^2 * coefficient of drag * area, so an 11% increase in density means an 11% increase in drag, so a ≈5.5% decrease in range. That's significantly less than typical cold weather range loss.
Most of the range loss comes from climate control. In a combustion car, the majority of the energy in the gasoline is turned into heat. In cold weather, you just dump some of this heat into the cabin to keep it warm. An EV's efficiency is a disadvantage in this case, as it needs to use energy from the battery to heat up the cabin.
I don't have the exact numbers there but the HVAC system should draw ~2kW at full throttle. Giving an average of, let say, 160Wh/km (speaking of a recent Tesla M3 for example) at highway speed. Over an hour of full throttle heating you would have consumed in heating an extra ~10% of what you spent to move the car. So OK, maybe air drag increase is not the worst offender here but it's not just the HVAC system.
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While writing this I searched a bit and according to this [1] when there is really cold temperature and the battery still haven't got warm, it can draw 5-6kW at the beginning. Anyway when driving motors heat up, the heat is used to warm the battery, the battery heats up as well and all that heat is used by the heat pump to warm the inside of the vehicle.
I have a PHEV and when I turn on the heat as I'm pulling out of my garage, the range is cut by 30%. This has nothing to do with drag since I'm backing out at 2 MPH. It's just about the HVAC system, which uses a lot of power. I typically just use the seat warmer, but when my kids are in the backseat I have to run the heat as well.
I very much doubt this. I've never seen this having a notably measurable effect on ICE vehicles in Massachusetts winters (which can be cold but aren't notably arctic).
I have to say that the "fun facts" included here are actually pretty cool. They are exactly the sort of thing one would want to use to explain the whats and whys of the ship to your kid.
I think the key here is mostly to go slow. Right now,if I'm bike commuting I need to keep up with cars or risk getting rear ended or tailgated or shouted at. Setting things up so you don't have to worry about cars while on your bike means you can bike at a more reasonable speed instead of 25mph.
Think beach cruiser bikes not guys in spandex on race bikes
Also infrequent cyclists are often overdressed. You don't need to get out the spandex, but if the weather permits dress so that you are slightly cold while standing still. That gives you the thermal budget to heat up from exercise without instantly sweating.
This is the fundamental problem. One an individual basis moving to a 8k square foot house in the suburbs is the thing to do. For the aggregate this means the mass transit gets worse, the traffic gets worse the emissions get worse, the tax base gets smaller.
The solution is policy. Use public money to make that 2 hour transit shorter and everyone wins, not just those of us with cash
As city dweller, I really would like less parking in my city.
Turns out surface parking is a better $/sqft than garages once you count maintenance. This means that the core part of the city where density is greatest is ringed by a 2-5 block wide wasteland of surface lots. Its not great. Especially now that work from home is a thing and the divide between people who live here and people who drive here to work is obvious because the suburb people aren't here any more but their parking spaces still are
The parking spaces are still there because the city's 'density' or 'daytime population' was pumped by ecologically unsustainable commutes.
The US has never had a high level civic planning process or ability. Housing ends up built where-ever, and it's often cheapest to go built it in places with less regulation. Like wild frontiers in not even states. Or in areas outside of city limits as a tax dodge. There also aren't formal processes for renewing areas; instead informally they're allowed to decay and crime rise, and eventually reach a point where it becomes 'economically viable' for building something new.
Those lots exist because there's still enough whatever is desired in the city you live in, probably too much retail and office space. Probably not enough apartment / condo / housing space, but none of those investors want to admit their market was over-valued and de-value the present investments so they'll happily keep supply low and rents high.
Looking forward to slapping a few quick games into this and distract the kids in a low bandwidth type style.